Fluid handling is a vast field with applications in power generation, materials handling, the petrochemical industry, sewage, drinking water and many other fields too numerous to list. One vexing problem in almost all fluid handling applications involves pumping fluids which contain particles or solids. The most efficient type of pump for the displacement of fluids is the impeller driven centrifugal pump. The centrifugal pump is most efficient at converting the drive shaft motor power into useful work capable of displacing fluids. The centrifugal pump operates by the rotation of an impeller. The impeller is typically constructed of a malleable material capable of deforming under varying stress and capable of passing entrained particulate matter. One difficulty with impeller driven centrifugal pumps is that the impeller is easily torn to pieces by solid materials whose diameter approaches the impeller diameter. In industrial applications pump failure is routinely experienced at great cost in both production time and material costs, often requiring tedious decontaminations or isolations of hazardous materials. Other applications raise other safety concerns from pump failure.
The most direct approach to prevent pump failure due to the presence of solids in the impeller is to use a screen or filter to strain the particulate matter from the fluid intake side of the pump. This method suffers from a significant shortcoming since the accumulation of solids on the filter or screen creates a pressure drop resulting in the steady decay of pumping flow rates. Eventually the screen becomes so enmeshed with solids that fluid passes through so slowly as to starve the pump and result in another type of failure from burning the pump out. This approach to the problem therefore requires that the filter be periodically cleaned, at the expense of valuable production time, to insure adequate flow rates to the intake side of the pump. Parallel sets of filters are often installed to avoid downtime. This approach involves additional capital expense, particularly in industrial applications in refineries and power generation units.
Another approach has been to develop alternative pump designs which do not suffer from the impeller shearing problems described above. In many applications involving mining and dredging, piston type pumps have been developed to permit the transport of particle-rich fluids without damage to the pump hardware. These designs, while addressing the solid particle problems, are inefficient.
For the first time, the present invention provides an apparatus to remove solids from a fluid stream on the intake side of a centrifugal pump without solid buildup on the separating device and without the decaying pressure drop problems associated with classical filtration. The apparatus is constructed of standard pipe joint parts. It requires no active maintenance and is easy to install and operate. It is applicable to a wide range of applications from the chemical processing industry, to site construction excavations, municipal water supplies, to electrical power generation. The apparatus incorporates proven principles of pressure vessel design and requires no additional training to operate even in highly dangerous applications.
It is therefore an object of the present invention to provide an apparatus for the removal of solids from fluids on the intake side of a centrifugal pump.
It is a further object of the instant invention to provide a novel separating apparatus which is constructed of conventional pipe parts, or derived from conventional parts.
It is another object of this invention to provide solid/fluid separation without a gradual increase in the pressure drop across the separating medium.
It is a still further object of this invention to provide a novel separating apparatus which is easy to maintain and repair.
It is an object of this invention to provide an apparatus which permits the transfer of fluids, containing solids, by diverting the entrained solids around the pump.
It is a further object to provide an apparatus which can increase flow rate without the addition of incremental power.
These and further objects of the instant invention will become readily apparent to those of ordinary skill in the art by reference to the instant specification and figures.